You need at least 4 targets that will live longer than 10s for it be effective. The only time I spam BB is when I have, oh fuck thats a guys pissed off at me.In heroics, HS cleave does more damage unless you literally pull a whole room. Which I have been known to do, but one BB generally works better so I can save other runs for mitigation.

You shouldn't use Death Strike whenever you can! First off, you should learn the fight and always be prepared for a massive hit. If there are none in a "mid-near future" (10-16s), then it's fine to DS away. You should time your Death Strikes for the hits, and always remember - While it feels awesome to build big blood shields, it's not as important as having consistent ones. If you're spamming Death Strike, you won't take as much damage as you would before, therefore giving you sub-optimal blood shields with minimal absorb. I know it sounds wrong, "Take more damage, it's better!", but it actually is. Not saying that you should drop to 20% hp and DS away, but don't spam DS just because you can. It should be used properly, otherwise it's not beneficial.

Rune strike? Meh. Depends.

Heart Strike/Blood Boil - Depends on spec. If you've specced RE, you'll want 1 blood rune ready at all times, just so your RE procc doesn't get wasted on a blood rune. After this, it's spamparty at Rune Strikes house. This is only if you've specced into RE tho.

"Below x% HP-chart" While it's a good idea... It's not. You should ideally "save" your IBF on every encounter for a specific part of the fight. The rest should be taken care of by juggling small CDs. Always think ahead, you should know when to pop your cooldowns before entering a fight. While @ 80% hp it's easier just to heal and get a BS, but since you're just spamming all your DS's away, I understand if that becomes difficult. (not meaning to be rude, just saying that's how it is)

Deathstrike is deffinately reactive. You would want to pop it right after taking heavy damage. This different from "shield" classes like warriors who time active mitigation to absorb your next big attack.

People jumping on him about not just using DS whenever available. Everyone seems to have missed where he said following this guide would have you operating at 80% efficiency, and he's right about that. Of course, timing DS is more beneficial, but this is a thread about someone just moving to DK Tanking, the flow chart above will get him through every heroic dungeon in this game, and I imagine Raid Finder as well. As he gets more comfortable he can delve into the true depth of DK Tanking.

DK Tanking has alot of things to manage, and managing them properly seperates the goods from the bads at high level progression. If you are running heroics or just use LFR, have fun spamming DS and watching little kids cry because you are out dpsing them.